I was a huge fan of this show during its 1990s heyday, so I approached the movie with mixed feelings. I liked it okay. Wasn't as awful as I'd feared it might be, wasn't quite as good as I'd hoped it would be.
I certainly liked the fact that Mulder and Scully were "together", but I was disappointed by the fact that they were simply "in a relationship" rather than actually married, as I felt it was inconsistent with Scully's character. The movie made it pretty clear that she'd returned to the practice of her Catholic faith in most other ways - working at a Catholic hospital, praying, etc. - so why wouldn't she get married to the man she was sharing her life with? As far as I could tell, there was no reason for them *not* to be married, other that Hollywood's reflexive prejudice against showing marriage as a positive, mutually supportive relationship.
The case itself I didn't much care for. I always thought of XF more as a mystery/sci-fi show and this was more of a horror movie, which has never been a genre I enjoy.
I was glad to see Skinner again!